Extension ladder



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July 10, 1951 Flled Aprll 26 1946 July 10, 1951 J. 1.. PAINTER, JR2,559,992

EXTENSION LADDER Filed April 26, 1946 2 Sheets-Sheet 2 I I! new tar .2John Z. Pa'z'rzz egdiz' a5 By Patented July 10, 1951 UNITED STATESPATENT OFFICE 2,559,992 EXTENSION LADDER John L. Painter, Jr., WestNewton, Pa.

Application April 26, 1946, Serial No. 665,177

My invention relates to improvements in extension ladders, the primaryobject in view being to provide an extension ladder of all metalconstruction, to conserve wood, and which is light in weight, yetstrong, inexpensive to manufacture, and equipped with easily operativepull means for extending the ladder adapted for locking the sameextended or contracted when relieved of pull thereon.

Other and subordinate objects, also comprehended by my invention,together with the precise nature of my improvements and the manifoldadvantages thereof will be readily understood when the succeedingdescription and claims are read with reference to the drawingsaccompanying and forming part of this specification.

In said drawings:

Figure 1 is a view in front elevation of my improved extension ladder,in a preferred embodiment thereof, showing the same extended,

Figure 2 is a view in side elevation, partly broken away,

Figure 3 is a fragmentary view in perspective of the extension section,

Figure 4 is a fragmentary view in longitudinal section taken on the line44 of Figure 1,

Figure 5 is a view in longitudinal section taken on the line 5-5 ofFigure 2 and drawn to an en larged scale,

Figure 6 is a fragmentary view in perspective of the main or basesection,

Figure '7 is a fragmentary view in horizontal section taken on the line'I'I of Figure 5, and

Figure 8 is a fragmentary view in vertical section taken on the line 8-8of Figure 5.

Reference being had to the drawings by numerals, my improved extensionladder, as shown, comprises a main, or base, section I includinglaterally spaced, parallel, side members 2 of channel iron form, and anysuitable light strong metal. The side members 2 on the confronting, orinner side faces thereof are formed with front and rear right anglededge flanges 3, 4 confronting to form therebetween longitudinal slots 5in the inner side faces of the members extending centrally thereof fromend to end of the same. The side members 2 function as guides for anextension section 6, to be described.

Rungs I of T-iron form are welded, or otherwise secured. as at 8, attheir ends'zto the rear flanges 4, and are spaced apart vertically withthe usual spacing therebetween and with flat sides uppermost so thatsaid rungs are of step-like form. As will be seen, the rungs I arearranged in the rear of the longitudinal center of the main 2 Claims.(01. 228-65) section 2 and in the rear of the slots 5. The purpose ofthis arrangement will presently be" clear. As best shown in Figure 8,the rungs I are arranged so that the uppermost fiat sides thereofincline toward the front of the mainsection I so that when said sectionis inclined upwardly and rearwardly, the uppermost flat sides of therungs will be positioned substantially horizontally to provideapproximately level steps, with the main section I arranged at thenecessary inclination.

The extension section 6 includes side members 9 vertically slidable inthe side members 2 of the base section I and constructed in the samemanner as said members 2 with the exception that the outer side faces ofsaid members 9 are formed with the longitudinal central slots I0corresponding to the slots 5 of said members 2. The rungs II of theextension section 6 are constructed and arranged in the same manner asthe rungs I of the main section I with the exception that said rungs I Iare secured to'the side members 9 in the longitudinal centers of saidmembers so that said rungs I I may pass into and out of the slots 5 inthe side members 2, and slightly for-' wardly of the rungs 1.

For sliding the extension section 6 outwardly and inwardly relative tothe base section I to extend and contract the ladder, respectively, thefollowing meansis provided.

A pull line, preferably in the form of a flat tape I2 is extendedslidably through a ring I3 swivellcd, as at I4 on the top rung I of thebase section I in the transverse center of said rung and so that saidtape provides a pendent free handgrip portion I5 and an attaching end I6both, preferably, in front of the rungs I and II. The attaching end I6is secured, as at H, to the center portion of a flexible wire pullmember I8 slidably extended upon opposite sides of its center downwardlythrough a tubular guide I9 of inverted V-shape suitably secured by aflange 20 to a rung II of the extension section .6 in the transversecenter of said section. From the guide I9, the member I8 inclinesdownwardly to a pair of tubular upwardly curved guides 2| suitably fixedon top of the rung I I immediately below the rung I I to which saidguide I9 is fixed, said guides 2I being arranged to extend into theslots 5 of the side member 2 at opposite ends of the rung II on whichthe same are fixed. At the terminals thereof, said member I8 is suitablyattached, as represented,'for instance, at 22 to the inner ends of apair of latch bolts 23 slidably extended through the inner side faces ofthe side members 9 and spring loaded, as at 24 to be projected outwardlyinto vertically spaced apertures 25 provided in the outer side faces ofthe side members 2 of the base section I. Collars 26 on the latch bolts23 slidably fitted in suitable guide bushings 21 on the side members 9guide said latch bolts in projection and retraction thereof and byengagement with the outer side faces of the side members 2 limitprojectin movement of said latch bolts. The bushings 21, as will beun'-' derstood, are arranged to play vertically in the slots of the sidemember 2. The apertures 25 are vertically spaced in correspondence withthe spacing of the rungs l, and H but slightly above rungs .1 of thebase section I so that when the said means comprising a pair of oppositebushlatch bolts 23 enter said apertures 25, the rungs" ll of theextension section 6 which are positioned between the side members 2 ofthe base section I will be slightly higher than the rungs I of said basesection. This is to provide for spacing the instep portion of the feeton top of such rungs l i without interference by the adjacent rungs l. v

I'he manner in which the described ladder is extended and contractedwill be readily understood. By pulling on the hand-grip portion 15 ofthe tape l2, with the ladder in proper position, a pull may be exertedon the member Hi to retract the latch bolts 23, in opposition to thesprings 24:, out of apertures 25 into which the may have been projected.Thus the extension section 6 is unlocked, or unlatched, from the mainsection i for sliding inwardly Or outwardly of said main section. Bycontinuin the pull on the hand-grip section IS, the latch bolts 23 willbe st pped. in fully retracted positions as the collars 26 fullycompress the springs 24, at which point, the extension section 9 will bepulled outwardly of the base section I. When the extension section 9 hasbeen extended to the desired position, the. handgrip portion l5 of thetape 12 may be released and theextension section held by hand until thelatch bolts 23 are projected by the springs 24. into the appropriateapertures 25 to lock the extension section 9 in selected extendedposition. By easing upon the pull on the hand-grip portion l5 of thetape I2 sufliciently to permit the xtension section 9 to move inwardlyof the base section i- (under the influence of gravity), the ladder maybe contracted to a desired extent and the extension section 6 locked, orlatched, to the main section I in the same manner as describedwith ingsfixed in the channels of the inner side members in hidden position,spring loaded latch bolts slidably retractile in said bushings andextending out of. said bottoms, a pair of upwardly curved tubular guideson one rung opposite said latch bolts, a flexible pull member ofinverted V-shape REFERENCES CITED The following references are of recordin the file of this patent:

UNITED STATES PATENTS Number Name Date 229,472 Rood June 29, 1880356,088 Barnes Jan. 18, 1887 428,995 Adley May 27, 1890 657,982 GardnerSept. 18, 1900 675,744 Lewis June 4, 1901 873,110 Williamson Dec. 10,1907 194 1 382 Wecker Jan. 23, 1934 2,016,196 Handfield Oct, 1, 19352,186,181 Steinlein Jan. 9, 1940 2,298,367 Nelson Sept. 22, 19422,542,398 Crumpton Feb. 20, 1951 FOREIGN PATENTS Number Country Date8,599 Great Britain 1840 7 144,733 Germany Sept. 26, 1903

